Improved High Performance Recycling of Polymers by Means of Bi-Exponential Analysis of Their Fluorescence Lifetimes

Technical polymers could be identified by means of their remarkably strong auto fluorescence. The mono-exponentially obtained time constants of fluorescence decay were applied for a rough assignment of the polymeric materials whereas bi-exponential analysis allowed a fine classification such as for special batches and for preceding contaminations. Chemically similar materials such as LDPE (low-density polyethylene), HDPE (high-density polyethylene) and UHDPE (ultrahigh-density polyethylene) could be as well identified as contaminations of mineral oil in PET (polyethylene terephthalate). Furthermore, the fluorescence spectra could be characterized by means of five Gaussian functions in the visible allowing a redundant assignment to the fluorescence lifetimes. Thus, efficient sorting of polymers was possible for high performance recycling

Effects of age at first birth on health of mothers aged 45 to 56

"Anhand der Daten des Survey of Health, Ageing and Retirement in Europe (SHARE) für 13 europäische Länder wird der Zusammenhang zwischen dem Alter der Mutter bei Erstgeburt und ihrer Gesundheit im Alter von 45 bis 56 Jahren untersucht. Im Vergleich zu Müttern, die ihr erstes Kind im mittleren Alter bekommen haben, zeigen sich signifikant höhere Erkrankungsrisiken unter jungen Erstgebärenden. In einem ersten Schritt wird gezeigt, dass dieser Effekt auch unter Berücksichtigung von Selektionseffekten, welche das Alter bei Erstgeburt bestimmen, weitgehend bestehen bleibt. Anschließend wird untersucht, ob sich der biosoziale Ansatz, der den negativen Effekt früher Geburten auf die spätere Gesundheit anhand geringerer sozialer und ökonomischer Ressourcen im Lebensverlauf von jungen Müttern erklärt, bestätigt. Die Ergebnisse zeigen jedoch, dass sich ein junges Alter bei Erstgeburt auch unter Berücksichtigung von gesundheitsrelevanten Ressourcen im Lebensverlauf negativ auf die Gesundheit auswirkt. Mögliche Erklärungen liegen in der Operationalisierung der gesundheitsrelevanten Ressourcen und in unbeobachteten Effekten. Aufgrund von Datenbeschränkungen konnten Indikatoren zur Bildungs- und Berufshistorie und zur sozialen Unterstützung, die vom Alter bei Erstgeburt abhängig sein können und die spätere Gesundheit beeinflussen, nicht berücksichtigt werden. Die Ergebnisse zeigen Mechanismen kumulativer sozialer Ungleichheit auf, wenn benachteiligte Frauen jünger Mütter werden und dadurch ihre Gesundheitsrisiken zusätzlich verstärkt werden." (Autorenreferat)"Employing the data from the Survey of Health, Ageing and Retirement in Europe (SHARE) for 13 European countries, we analyse the relationship between mother's age at first birth and her health at age 45 to 56. Compared to mothers who gave birth at middle age, we found a significantly higher risk of illness among young first-time mothers. In a first step, we show that this effect largely remains after controlling for selection effects which determine age at first birth. Next, we examine whether the biosocial view could be confirmed. This approach explains the negative effect of early births on later health through a lack of social and economic resources during young mothers' life course. Thus, fewer resources are expected to affect health outcomes. However, the results indicate that the negative effect of young age at first birth remains even after controlling for health-related resources throughout the life course. The operationalisation of health-related resources as well as unobserved effects might be regarded as possible explanations for this. Due to data restrictions, indicators for educational history, job history and social support, that are all likely to depend on age at first birth and also affect later health, could not be taken into account. The results identify mechanisms of cumulative social inequality when disadvantaged women become mothers at younger age and thereby further increase their risk of disease." (author's abstract

High Performance Recycling of Polymers by Means of Their Fluorescence Lifetimes

Technical polymers could be identified by means of their remarkably strong autofluorescence. The time constants of this fluorescence proved to be characteristic for the individual polymers and can be economically determined by integrating procedures. The thus obtained unequivocal identification is presented for their sorting for recycling. Furthermore, polymeric materials were doped with fluorescent dyes allowing a fine-classification of special batches

Von Donaustrom zu Donauwelle. Die Entwicklung der Eigennamenkomposition von 1600–1900

Despite their high frequency in present-day language, German proper name compounds have received little attention in the linguistic literature. It has been assumed that this pattern is rather recent, and possibly a loan from English. Focusing on the period between 1600 and 1900, the paper provides evidence against this claim. More specifically, I argue that the development of proper name compounds can only be properly described if proper name compounds that are names themselves (e. g., Martin-Luther-Universität ‘Martin Luther University’) are strictly distinguished from those that are common nouns (e. g., Nilfahrt ‘Nile ride’). It is shown that both types develop differently, and in particular that common noun compounds undergo a functional extension in this period. In this connection the paper also discusses the idea of proper name compounds as competitors of the genitive and it compares proper name compounds and alternative constructions with respect to the concept of the “Nominalklammer” (nominal frame)

Fluorescent aryl naphthalene dicarboximides with large Stokes shifts and strong solvatochromism controlled by dynamics and molecular geometry

A series of highly fluorescent 4-aryl substituted naphthalene dicarboximides were efficiently prepared via metal organic C–C-coupling reactions. The obtained push–pull fluorophores display a distinct positive solvatochromism of the fluorescence. These optical properties are shown to be significantly dependant on the molecular geometry. Corresponding to TICT, a twist between the donor and the acceptor moiety enhances the intramolecular charge transfer resulting in such pronounced solvatochromism. Complete orthogonalisation inhibits the fluorescence. An intentional skew arrangement leads to solvent-adjustable chromophores with high fluorescence quantum yields and Stokes shifts of more than 1.6 e

Pipeline Vibrations And Pressure Pulsations—Reasons And Solutions

TutorialEvery pump has some kind of non-continual conveying behavior or effect. Because the conveyed liquids as well as the pipelines and support structures in the connected system are elastic, the conveyed liquid will transport these fluidmechanical or -acoustical dynamics into the connected system and can excite them to vibrations up to critical resonance situations. The consequences of these dynamics can be fatigue ruptures or not acceptable deformations at or of all connected parts or structures as well as damages. This tutorial covers all these topics, describes pump characteristics, how a system can react and what can be done to avoid pressure pulsations or vibrations in a system. Centrifugal pumps or vane cell pumps i.e. always generate vane passing frequencies resulting in certain pulsations while reciprocating machinery and also some rotating positive displacement pumps have pulsating conveying behaviors. In connection with these behaviors also pressure shocks and water hammers can occur. Pipelines or cantilevers but also more complex structures of process plants instead behave like strings or the corpus of a guitar. They can vibrate like acoustical music instruments and therefore also can be calculated like these. When the system is simple analytical equations can be used to determine the natural frequencies. Based on this, a stable and stiff system can be designed. But when the system gets more complex only numerical methods can generate reliable results. When the natural frequencies and the vibrating behaviors are available the correct damper design or damper combination can be selected